Improvement in prepared leather



UNITED STATES PATENT OFFICE OLDIN NICHOLS, OF MEDFORD, MASSACHUSETTS.

lMPROVEMENT IN PREPARED LEATHER'.

Specification forming part o1 Letters Patent No. l 70.962, dated December 14, 1875; application led November 11', 1875.

To'all whom z'tmay concern l Be it known that I, OLDIN NICHOLS, of Medford, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Prepared Leather, of which the following is a specification This invention relates to a prepared leather for insoles, heels, stitfeners, trunks, and for other purposes for which it may be adapted.

Figure 1 shows a top view of a piece of this prepared leather; Fig. 2, a section thereof; Fig. 3, an insole cut therefrom, and flig.` 4 a built-np heel.

The object of my invention is to produce a cheap yet serviceable prepared leather for insoles, heels, &c., as a substitute for all leather, or for leather-board;

Leather insoles, at the present high price of leather, cannot be u'sed except in the very best work; therefore itis common to employ leather-board, a material containing but avery small percentage of leather,'and into which the pegs and other fastenin gs do not stick and hold as in leather, for the material has not the elasticity of leather, or its powers of cohesion and it is harder and inore rigid.

This prepared leather is composed almost entirely of leather, and of a refuse leather heretofore considered of no value Whatever-viz., sheepskin and other skivings. The skivings made in the tanning and treatment of sheepskins are thin, and, when removed, roll up, and are considered of no value. I take these and other skivings, and pass them into and through a picker composed of a rapidly-revolving cylinder set With teeth, that tear up or shred the skivin gs, and the torn or shredded skivin gs are then,in a dry state,kept until'ready for use. AI place about four parts of rosin and one of sal-soda or potash, or other article that will cutthe rosin, in a vat or vessel containing a proper quantity of water-usually about two hundred gallons-and, by means of steam, so as to get an excessive heat, I boil the rosin and sal-soda for three or four hours, or until the -rosin is cut or dissolved, or substantially so, leaving a strong solution of alkaline rosin. I employ this alkaline-rosin solution as the liquid to form a pa-ste, mixing the same with our to the consistency of ordinary paste and to about one hundred pounds-of the torn or shredded skivings or leather ina dry state I the alkaline rosin the leather-will take up, and i then Iadd the rosinpaste, mixing the same thoroughly; and this preparation gives to the sole more rigidity, and the increased amount'of' rosin also gives body to the mixture. and serves to make a holding-surface, against which the sides of the pegs drivenintothe so'le hold closely, substantially as closely, and, in my judgment, fully as firmly, if not more `firmly, than in real leather. The alkaline in the rosin acts ou the oil and greasein theleatherorskivings, and dissolves and destroys it, and leaves'tbe rosiu thoroughly incorporated with the skivings, but in a pasty state. The leather, torn and mixed substantially in this manner, is then placed in i a mold between what is -known assplits, or pieces of split leather, the split leather covering the same at bottom and top, and the pulpy mass of mixed leather may be prevented from escaping as the material is being moldedin slabs or compressed by placing on the upper side of the under piece of splitleather, or near its edge, pieces of skivings opened out, or pieces of fibrous cloth, the pieces being folded over on the mass of torn leather fitted into the mold just before the top piece of splitleather is placed in position. These edgingpieces,.pasted to the splits by the rosin paste, prevent the torn `and pulpy leather from escaping as the top piece of split leatheris being pressed down. After being removed from the mold the slabs or pieces so formed are placed in a drying-room, or allowed to partially dry, and then the slabs are run between powerful compressing-rollers, thoroughly compressing the material together, making a slab of an even thickness, and producing a prepared-leather' slab of substantially uniform solidity, and an excellent substitute for leather. During the process I may add shellac toA the paste, using it with or instead of rosin-to add to the water-proof qualities of the prepared leather but the rosin is preferred.

edge which easily takes a polish, the'rosinincorporated throughout the mass when the rosin was in a dissolved state assisting in the polishing, and therefore the prepared leather is specially adapted for heels but in the manufacture of heels I prefer to make the outer or top lift of real leather.,

This processof making a prepared leather by incorporating with waste leather an alkaline solution of rosn and paste to give the substance rigidity and great power of adhesion to the pegs or stitches, and to easily take a polish, may be carried out to great advantage by using between the splits forming the inner and outer sides of the prepared leather, instead of `the torn and mixed leather, ordinary skiyjings, the same being laid and past'- ed, one overtheother, en. masse, in amold, and subjected to pressure, and subsequently dried and subjected to the action of rollers or equivalent, to compressand consolidate the slab or form. These slabs or forms may be formed by hand in lmolds, preferably a foot or more in length, and of awidth to permit soles or heels to be died out;'or I may make the slabs in longer or wider pieces in a machine provided with molds, and in which a follower is arranged to work within the mold. Then I may dispense with the enveloping-pieces of leath- 'er' or cloth, the sides of the mold preventing the escape of the leather from between the splits, and the mold may be of sole' or other form.;

lHl

The quantity of alkali added to the water in which the rosin is boiled is suicient te cut and permit vthe rosin to dissolve and mix with the water, and the quantity ofwater employed depends on the strength it is required the alkaline-rosin solution to have. Usually, to one hundred pounds rosin and twenty-five pounds sal-soda I employ two hundred gallons of water, and the strength of the alkaline solution.

Ido not limit myself to the exact proportions named, as they may be varied, and glue might be added to give stiffness. This torn leather might be applied between canvas or cloth, and be made in indefinite-length, and of suitable width. This paste will form the subject-matter of another application. An article of prepared leather might be made by using torn or shredded leather, as described, with other paste than that described; but the paste described by me is the best that can, in4v my judgment, be used.

I claim- .leather composed of pieces-or splits of real leather or fibrous material, with an intermediate filling of torn yor shredded leather, and an alkalinerosiu paste, substantially as described.

2. The process of manufacturing'prepared leather, consisting in mixing, with vtorn or 4shredded leather or skivings, an alkalinerosin paste, then the lapplication of such mixed leather and paste betweenlayers of leather or cloth, and molding, drying,and compressing the same into a uniform layer, substantially as described. c,

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

OLDIN NICHOLS.

Witnesses:

' G. W. GREGORY,

S. B. KIDDER.

1. As an article 'of mannfacture,prepared Y 

